It's a testimate to how horrible the Royals offense has been this season. As bad as they have been in Shields starts, they have been even worse in Ervin Santana's starts (3.36 RS) and almost as bad in starts by Guthrie (3.80 RS). So it's not really bad luck by Shields and it isn't something I would expect to get much better as the year goes on.
The Royals are on pace for 88 team homeruns. The last time an AL team hit fewer than 100 homeruns in a season was 1992 (if you discount the 1994 Brewers who hit 99 in a strike shortened season of 113 games). Alex Gordon is on pace to lead the team with 12 HRs. I'm still trying to verify, but this might be the lowest total to lead an AL team since the 1940s.